Joseph Goldstein and J. David Goodman

New York Times News Service

NEW YORK - In the streets of Brooklyn, a local rap artist named Cuame Nelson was recording a new music video when someone called out his stage name.

The rapper, fresh out of a stint at Rikers Island, turned toward the voice, expecting to see a fan or friend. Instead, he saw several plainclothes police officers, one of them wearing a shirt bearing the name of Nelson’s group.

Nelson, 21, is among several local rappers to discover recently that their devoted listeners include police officers and prosecutors. They listen not for artistic merit, but to pick apart the lyrics and examine music videos posted on YouTube in hopes of a better understanding of gang rivalries and the dynamics behind recent shootings.

In December, for instance, investigators said that a case against 11 gang members had been aided by a music video, produced by a minor group called Dub Gang Money. The video, according to a police lieutenant, Peter Carretta, provided evidence that those arrested were part of an established gang and associated with one another.

The Police Department’s interest in music videos coincides with a broad shift in patrol strategy: As the department de-emphasizes stop-and-frisk tactics, it has assigned scores of street officers to patiently pursue longer-term investigations against neighborhood gangs, particularly the youth gangs known as crews or sets.

Directed by prosecutors to build evidence that individual shootings are part of larger criminal conspiracies, officers are listening to local rappers for a better sense of the hierarchy of the streets.

“You really have to listen to the songs, because they’re talking about ongoing violence,” said Officer Fred Vanpelt, who is part of an anti-gang squad.

Vanpelt said that Nelson, known on his videos as Murda Malo, was part of a hip-hop collective called Addicted to Cash, or ATC. But police investigators said ATC was also a criminal organization: the latest iteration of a street crew known for shooting at its rivals.

Police Sgt. George Tavares said that one rap video in particular was “a keystone piece of evidence” against a crew that his officers were in the midst of building a case against. But he declined to provide particulars out of fear that the musicians would take it down.

“It’s important to us,” he said.

The risk that the police might be listening is something of a professional hazard to the rappers.

“It’s a double-edged sword,” said Patrice Allen, 35, who manages Nelson and another ATC member, K-Dot, whose name is Karon Stanley. Both are under felony indictment in a Brooklyn gang case. “If you have that much passion and love for the music, I guess you have to deal with it. That’s just what comes with the music. It’s the bitter and the sweet, you know?”

It once could take months or years to translate the raw tales of street life from demo tapes to record deals, airtime and music videos. But rappers are releasing lyrics and videos directly to YouTube, giving local talent - and local beefs between gangs - much wider audiences.

Terry Holder, the mother of a young rapper known to friends as Na Boogz, recalled, “The day after he got arrested, he was supposed to be dropping his mix CD.” Friends posted it on YouTube, she said.

Rap videos by Na Boogz, whose name is Shaquille Holder, were noted in the indictment against him and nine other members of WTG, a youth gang in the Bronx. The indictment focuses on violence between two gangs, WTG and Dub City, which were once closely affiliated and whose members grew up together as friends.

After the two groups split, Na Boogz took to YouTube with a rap video addressing a rival. Prosecutors say the lyrics attack a former friend and fellow rapper, Quaysean Haywood, who switched allegiances to Dub City.

“You’re not a big homey, you’re a little youth,” he says in an insult-laced rap. “You couldn’t shine over here, so you switched crews.”

The practice of disrespecting rivals in rap is well established; the same with rappers claiming to be “the worst guy in the neighborhood,” said Bridget G. Brennan, the special narcotics prosecutor for New York City. “That’s been around forever.”

“But there’s now a much bigger audience - it’s not just that the whole neighborhood knows about the dispute,” she added. “You can get tens of thousands of hits on a YouTube video. It’s a much bigger arena.”

Indeed, Holder’s rap video about Haywood has been viewed more than 100,000 times.

Holder said her son had begun to resent Haywood, a longtime friend, after her son was twice arrested on gun possession charges for weapons that he claimed belonged to Haywood. “Every time Quaysean shows up with a gun, my son gets in trouble,” she said.

Standing under an elevated train one fall afternoon, Nelson said he had spent tens of thousands of dollars on bail and lawyers’ fees after he was arrested, money that he would have spent on studio time. He is not accused of taking part in the shootings but rather of being a member of the surrounding conspiracy, a felony charge that he disputes.

“I’m not in any gang,” he said. “We have copyrights for our organization; we are a music group. OTS Entertainment. ATC Entertainment. This is a music group, you dig?”

But, he acknowledged, “I can’t say that everybody is living the straight and narrow life.”

In November, Nelson was rearrested and indicted on new conspiracy charges related to the shooting of a grand jury witness in late 2012; prosecutors said that more than three months before the shooting, he and two ATC members had possessed a loaded gun in a cab. His manager, Allen, said the police had arrested Nelson outside a Brooklyn club just before he was to perform there. “We were walking in and they rushed him,” Allen said. Nelson is currently in jail.

“A lot of people still out in these streets,” he said before his arrest. “But if they do a crime, you can’t make that fall back on the one that’s trying to make it out of the hood. If they lock us up, who’s going to get us out of the hood?”

Rappers often stand accused of being central players in the city’s most endemic gun violence between rival crews, if not always directly in the shootings themselves, than in the conspiracies underpinning them.

Brennan, the special narcotics prosecutor, said that the indicted rappers were not “like the Greek chorus describing how events unfolded.”

“They’re generally involved in gunplay and drug dealing, not just sitting on the sidelines humming tunes,” said Brennan, who said she had seen the videos of Na Boogz and Quaysean Haywood.

While awaiting his trial, Stanley released a song describing jail life and his concern over turncoat crew members. One song describes a mother’s anger at her son’s lies and the presence of a gun in the house. Rapping as K-Dot, he claims to be “Top 5,” which, investigators theorize, refers to the hierarchy of either ATC or its predecessor group, the Hood Starz.

If he were to be among the top five in either group, that would be a much loftier position than where the prosecutors had placed him in January 2011, when they described the charges against him and more than 40 other accused crew members.

The arrests were part of a takedown of the Hood Starz and Wave gangs, which had been warring. Their gunplay and stabbings had resulted in six deaths and 38 people being wounded.

The court case against Holder underscores just what a wide audience was reached by the young man who rapped about the rivalries that spawned shootouts. Holder, according to a legal filing by prosecutors, received a text message from someone a borough away who, after watching Na Boogz’s videos, wanted to enlist.

“I’m from Queens but I watch all ya videos,” the text message read. “Imma trying be down with the WTG Move.”

Holder texted back that, if the person wired him $125 through Western Union immediately, “you can be WTG under me and b official.”

Michael Schwirtz contributed reporting